Abstract: | Measurement of the initial rates of removal of limonin and naringin from grapefruit juices by several polystyrene and polyacrylic adsorbents has allowed these adsorbents, in the forms as supplied, to be ranked in their order of kinetic effectiveness for removal of the two bitter principles. Partition coefficients of bitter principles between juice and polystyrene adsorbent resins show that the capacity of such resins for naringin increases with specific surface area, but the capacity for limonin appears to increase with specific pore volume. With respect to titratable acid, the two weak base resins, Amberlite IRA-93 and Duolite A378, were equally effective both kinetically and in their capacity for titratable acid; both adsorbed somewhat less than 1 mol of titratable acid from grapefruit juice per equivaient of weak base resin. |